There are several kinds of TFT (Thin Film Transistor) liquid crystal panels, including amorphous silicon TFT liquid crystal panels with low electron mobility, and polysilicon TFT liquid crystal panels with relatively high electron mobility. To reduce cost and improve reliability, some polysilicon TFT liquid crystal panels and the like have a portion of a driver circuit formed thereon taking account of the characteristic mentioned above. Gate driver circuits, which, among all driver circuits, operate at relatively low speed, can be readily formed on the liquid crystal panel.
FIG. 13 is a diagram illustrating the configuration of a conventional liquid crystal display device. In the liquid crystal display device shown in FIG. 13, a pixel array 91 and a gate driver circuit 94 are formed on a liquid crystal panel 90, and a control circuit 92 and a source driver circuit 93 are provided outside the liquid crystal panel 90. In FIG. 13, the gate driver circuit 94 is positioned to the left of the pixel array 91 on the liquid crystal panel 90. There may or may not be some circuit positioned to the right of the pixel array 91.
FIG. 14 is a diagram illustrating in detail the gate driver circuit of the liquid crystal display device shown in FIG. 13. As shown in FIG. 14, the gate driver circuit includes a shift register 95 and a plurality of amplifier circuits 96. The amplifier circuits 96 amplify outputs from the shift register 95, thereby driving gate lines provided in the pixel array 91. In conventional liquid crystal display devices, the amplifier circuits 96 are configured by connecting a plurality of CMOS switches in multiple stages.
Note that Patent Documents 1 and 2 provide disclosures relevant to the invention of the present application, concerning gate driver circuits connected at opposite ends of gate lines.
[Patent document 1] Japanese Laid-Open Patent Publication No. 2000-276110
[Patent document 2] Japanese Laid-Open Patent Publication No. 2002-23712